1. Field of the Invention
The present invention relates to a laser pen, and more particularly to a laser pen with a safety power cutoff device.
2. Description of the Related Arts
A conventional laser pen 80 in accordance with the prior art shown in FIG. 5 comprises a barrel 82, a plurality of batteries 84 mounted in the barrel 82, a laser device 85 mounted in the barrel 82 for emitting laser light outward from the barrel 82 and including a circuit board 86 connected to one of the batteries 84, and a press button 88 detachably contacting the circuit board 86. When the press button 88 is pressed to touch the circuit board 86, the laser device 85 will emit a beam of laser light outward from the barrel 82. However, when a user is writing with the laser pen, he may unintentionally touch and press the press button 88 to emit the laser light outward from the barrel 82 to project onto the user""s eyes, thereby easily hurting the user""s eyes.
In accordance with one aspect of the present invention, there is provided a laser pen comprising a metallic barrel having an upper portion and a lower portion; a laser device mounted in the upper portion of the metallic barrel; a safety power cutoff device including an insulating tube secured in the lower portion of the metallic barrel and having an upper portion and a lower portion; at least one battery received in the upper portion of the insulating tube and electrically connecting to the laser device; a reservoir tube having a top portion including a metallic contact head movably mounted in the lower portion of the insulating tube and detachably contacting the at least one battery; and a rotating device mounted on the lower portion of the metallic barrel and engaged with the metallic contact head of the reservoir tube for moving the metallic contact head.
The insulating tube includes a receiving chamber defined in the upper end thereof for receiving the at least one battery, and a guide chamber defined in the lower portion thereof for movably guiding the metallic contact head of the reservoir tube. The receiving chamber has a diameter greater than that of the guide chamber, thereby defining an annular holding shoulder therebetween for stopping the battery.
The laser device includes a fixing sleeve having a lower portion secured in the upper portion of the metallic barrel and an upper portion protruding outward from the metallic barrel, a cover secured on the upper portion of the fixing sleeve, a metallic light source housing secured to the lower portion of the fixing sleeve, a circuit board having a first side connected to the light source housing, a conducting spring mounted between a second side of the circuit board and the at least one battery, a press button switch mounted on the circuit board, and a press button slidably extending through the metallic barrel and detachably engaged with the press button switch.
The rotating device includes a metallic support tube secured in the lower portion of the insulating tube, a metallic engaging portion mounted on a lower portion of the support tube and secured to the lower portion of the metallic barrel, a metallic slide tube slidably mounted in the support tube and securely engaged with the metallic contact head of the reservoir tube for moving the metallic contact head, and a pen head rotatably mounted on the lower portion of the support tube and engaged with the slide tube for moving the slide tube.
The slide tube includes an inner thread, and the contact head of the reservoir tube includes an outer thread screwed into the inner thread of the slide tube.
The laser pen further comprises a conducting spring mounted on the reservoir and connecting between the metallic contact head of the reservoir tube and the metallic support tube.
Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings.